Method to prepare bis(haloimides)

Abstract

Bis(halophthalimides) are prepared in mixture in an organic liquid such as ortho-dichlorobenzene or anisole, by a reaction at a temperature of at least 150° C. between at least one diamine compound and at least one halophthalic anhydride in the presence of imidization catalyst. The reaction mixture is maintained at about 15% by weight solids content and rich in the halophthalic anhydride by constantly monitoring the reaction mixture using analytical methods such as high performance liquid chromatography. The product mixture may be directly employed in the direct preparation of polyetherimides, and similar slurries may be employed to prepare other polyether polymers.

What is claimed is: 
     
       1. A method for preparing a bis(halophthalimide), said method comprising sequentially:
 (A) preparing a mixture comprising at least one halophthalic anhydride and at least one solvent wherein the mixture has a temperature greater than 150° C., 
 (B) adding to the mixture formed in step (A) at least one molten diamine to form a reaction mixture, said reaction mixture being characterized by “an initial molar ratio of halophthalic anhydride to diamine”, wherein the at least one molten diamine has the formula H 2 N-A 1 -NH 2  wherein A 1  is a C 2 -C 40  divalent aromatic radical; 
 (C) heating the reaction mixture formed in step (B) to a temperature of at least 150° C., and removing water of imidization; 
 (D) analyzing the reaction mixture formed by the combination of steps (A)-(C) to determine the initial molar ratio of halophthalic anhydride to diamine; and 
 (E) adding anhydride or diamine to the mixture formed by the combination of steps (A)-(C) to achieve a “corrected molar ratio” of halophthalic anhydride to diamine, said initial molar ratio and corrected molar ratio being in a range between about 2.01 and about 2.3, and 
 (F) adding sodium phenyl phosphinate imidization catalyst to the mixture and heating to a temperature of at least 100° C., to obtain a bis(halophthalimide) product mixture that is substantially free of water. 
 
     
     
       2. The method according to  claim 1  wherein said analyzing the reaction mixture formed by the combination of steps (A)-(C) to determine the initial molar ratio of halophthalic anhydride to diamine, comprises determining a concentration of halophthalic anhydride, a concentration of by-product halophthalic acid, and a concentration of intermediate monophthalimide monoamine in the reaction mixture formed by the combination of steps (A)-(C). 
     
     
       3. The method according to  claim 1  wherein said bis(halophthalimide) has structure I 
       
         
           
           
               
               
           
         
         wherein X 1  and X 2  are independently fluorine, chlorine, bromine or iodine; and Q is a C 2 -C 20  divalent aliphatic radical, a C 2 -C 40  divalent aromatic radical, or a C 4 -C 20  divalent cycloaliphatic radical; p is independently at each occurrence an integer ranging from 1 to 4. 
       
     
     
       4. The method according to  claim 1  wherein the halophthalic anhydride is 4-chlorophthalic anhydride, 3-chlorophthalic anhydride, 4-fluorophthalic anhydride, 3-fluorophthalic anhydride, or a mixture comprising at least two of the foregoing. 
     
     
       5. The method according to  claim 1  wherein the solvent is selected from the group consisting of chlorobenzene, o-dichlorobenzene, anisole, toluene, xylene, and mesitylene. 
     
     
       6. The method according to  claim 1  wherein the solvent is o-dichlorobenzene. 
     
     
       7. The method according to  claim 1  wherein the at least one diamine is selected from the group consisting of oxydianiline, and bis(4-aminophenyl)sulfone. 
     
     
       8. The method according to  claim 1  wherein said diamine is selected from the group consisting of aromatic diamines III and diamines IV 
       
         
           
           
               
               
           
         
         wherein R 1  and R 2  are independently at each occurrence a halogen atom, a nitro group, a cyano group, a C 2 -C 20  aliphatic radical, a C 2 -C 40  aromatic radical, or a C 4 -C 20  cycloaliphatic radical; and “n” and “m” are independently integers ranging from 0 to 4. 
       
     
     
       9. The method according to  claim 8  wherein the aromatic diamine is selected from the group consisting of meta-phenylene diamine and para-phenylene diamine. 
     
     
       10. The method according to  claim 1  wherein the temperature of the reaction mixture in step (C) is at least 200° C. 
     
     
       11. The method according to  claim 1  wherein the halophthalic anhydride, and the diamine when taken together are present in an amount corresponding to an initial solids content of the reaction mixture in a range from about 5% to about 25% by weight. 
     
     
       12. The method according to  claim 1  wherein said analyzing comprises analysis by liquid chromatography, gas chromatography, or a combination thereof. 
     
     
       13. The method according to  claim 1  wherein at least one of steps (A)-(C) and (E) is performed in a reactor free of water retention zones. 
     
     
       14. The method according to  claim 1  wherein at least one of steps (A)-(C) and (E) is performed in a reactor equipped with at least one flush-mounted valve. 
     
     
       15. The method according to  claim 1  wherein step (E) comprises distilling a mixture of water and organic components, to produce a product mixture that is substantially free of water and a distillate comprising water, solvent, unreacted halophthalic anhydride, and diamine. 
     
     
       16. The method according to  claim 15  wherein said distillate is subjected to water removal and recycling. 
     
     
       17. The method according to  claim 16  wherein said recycling comprises at least one process step selected from the group consisting of (a) preparing a mixture comprising at least one halophthalic anhydride and at least one solvent, (b) adding at least one diamine to the mixture comprising at least one halophthalic anhydride and at least one solvent, to form a reaction mixture, wherein a portion of the at least one of said halophthalic anhydride, said solvent, and said diamine is provided by said distillate. 
     
     
       18. The method according to  claim 15  wherein said distilling is carried out at superatmospheric pressure. 
     
     
       19. The method according to  claim 1  wherein each of steps (A)-(C) and (E) is characterized by a percent solids content, said percent solids content being less than about 17% solids. 
     
     
       20. The method according to  claim 1  wherein in step (B), said diamine is added dropwise. 
     
     
       21. The method according to  claim 1  wherein step (C) and step (E) comprise distilling water from the reaction mixture through a condenser maintained at a temperature greater than the boiling point of water and less than the boiling point of the solvent, wherein the boiling point of the solvent is greater than the boiling point of water. 
     
     
       22. The method according to  claim 21  wherein said distilling is carried out at a pressure of at least 1 atmosphere. 
     
     
       23. The method according to  claim 21  wherein a difference between the boiling point of water and solvent is at least 20° C. 
     
     
       24. A method for preparing a bis(chlorophthalimide); said method comprising sequentially:
 (A) preparing a mixture comprising 3-chlorophthalic anhydride, 4-chlorophthalic anhydride and at least one solvent having a temperature greater than 150° C.; 
 (B) adding to the mixture formed in step (A) at least one molten aromatic diamine, to form a reaction mixture, said reaction mixture being characterized by an initial molar ratio of 3-chlorophthalic anhydride and 4-chlorophthalic anhydride to aromatic diamine, wherein the at least one molten diamine has the formula H 2 N-A 1 -NH 2  wherein A 1  is a C 2 -C 40  divalent aromatic radical; 
 (C) heating the reaction mixture formed in step (B) optionally in the presence of an imidization catalyst, to a temperature of at least 150° C., and removing water of imidization; 
 (D) analyzing the reaction mixture formed by the combination of steps (A)-(C) to determine the initial molar ratio of 3-chlorophthalic anhydride and 4-chlorophthalic anhydride to aromatic diamine; and 
 (E) adding a mixture of 3-chlorophthalic anhydride and 4-chlorophthalic anhydride, or aromatic diamine to the reaction mixture formed by the combination of steps (A)-(C) to achieve a corrected molar ratio of 3-chlorophthalic anhydride and 4-chlorophthalic anhydride to aromatic diamine, said initial molar ratio and corrected molar ratio being in a range between about 2.01 and about 2.3, and 
 (F) adding sodium phenyl phosphinate imidization catalyst to the mixture and heating to a temperature of at least 100° C., to obtain a bis(chlorophthalimide) product mixture that is substantially free of water. 
 
     
     
       25. A method for preparing a bis(4-chlorophthalimide); said method comprising sequentially:
 (A) preparing a mixture comprising 4-chlorophthalic anhydride and orthodichlorobenzene having a temperature greater than 150° C.; 
 (B) adding to the mixture formed in step (A) a molten mixture of meta-phenylene diamine and para-phenylene diamine, to form a reaction mixture, said reaction mixture being characterized by an initial molar ratio of 4-chlorophthalic anhydride to meta-phenylene diamine and para-phenylene diamine, said adding being carried out and removing water of imidization; 
 (C) heating the reaction mixture formed in step (B), to a temperature of at least 150° C.; 
 (D) analyzing the reaction mixture formed by the combination of steps (A)-(C) to determine the initial molar ratio of 4-chlorophthalic anhydride to meta-phenylene diamine and para-phenylene diamine; and 
 (E) adding 4-chlorophthalic anhydride, or a mixture of meta-phenylene diamine and para-phenylene diamine to the reaction mixture formed by the combination of steps (A)-(C) to achieve a corrected molar ratio of 4-chlorophthalic anhydride to meta-phenylene diamine and para-phenylene diamine, said initial molar ratio and corrected molar ratio being in a range between about 2.01 and about 2.3, and 
 (F) adding sodium phenyl phosphinate imidization catalyst and heating to a temperature of at least 100° C. to obtain a bis(4-chlorophthalimide) product mixture that is substantially free of water. 
 
     
     
       26. The method according to  claim 1 , wherein A 1  is a C 6 -C 40  divalent aromatic radical. 
     
     
       27. The method according to  claim 1 , wherein the at least one molten diamine is selected from the group consisting of 1,4-diaminonaphthalene, 2,6-diaminonapthalene, 4,4′diaminobiphenyl, oxydianiline, bis(4-aminophenyl)sulfone, meta-phenylene diamine, para-phenylene diamine, 2,4-diaminotoluene, 2,6-diaminotoluene 2-methyl-4,6-diethyl-1,3-phenylenediamine, 5-methyl-4,6-diethyl-1,3-phenylene diamine, 1,3-diamino-4-isopropylbenzene, and combinations thereof. 
     
     
       28. The method according to  claim 24 , wherein A 1  is a C 6 -C 40  divalent aromatic radical. 
     
     
       29. The method according to  claim 24 , wherein the at least one molten diamine is selected from the group consisting of 1,4-diaminonaphthalene, 2,6-diaminonapthalene, 4,4′diaminobiphenyl, oxydianiline, bis(4-aminophenyl)sulfone, meta-phenylene diamine, para-phenylene diamine, 2,4-diaminotoluene, 2,6-diaminotoluene 2-methyl-4,6-diethyl-1,3-phenylenediamine, 5-methyl-4,6-diethyl-1,3-phenylene diamine, 1,3-diamino-4-isopropylbenzene, and combinations thereof. 
     
     
       30. The method according to  claim 1 , wherein the initial molar ratio is from 2.01 to about 2.3. 
     
     
       31. The method according to  claim 1 , wherein the initial molar ratio is from about 2.03 to about 2.3.